UsingSyslog - Revision history

JulienB: /* Tips */

2025-10-10T12:52:47Z

Tips

← Older revision		Revision as of 14:52, 10 October 2025
Line 110:		Line 110:
	== Tips ==		== Tips ==
	* By default logs are not persistent (/var/log points to /tmp). To have persistent logs with rotation every 1Mbytes, one can try to add this to his post_build.sh script:		* By default logs are not persistent (/var/log points to /tmp). To have persistent logs with rotation every 1Mbytes, one can try to add this to his post_build.sh script:
	<~~code~~ source="bash">		<source lang="bash">
	# for persistent and rotating log messages		# for persistent and rotating log messages
	rm -rf $1/var/log		rm -rf $1/var/log
	mkdir $1/var/log		mkdir $1/var/log
	sed -i -e 's/SYSLOGD_ARGS=""/SYSLOGD_ARGS="-s 1024 -b 10"/' $1/etc/init.d/S01syslogd		sed -i -e 's/SYSLOGD_ARGS=""/SYSLOGD_ARGS="-s 1024 -b 10"/' $1/etc/init.d/S01syslogd
	</~~code~~>		</source>

JulienB at 12:50, 10 October 2025

2025-10-10T12:50:43Z

← Older revision		Revision as of 14:50, 10 October 2025
Line 107:		Line 107:
	...		...
	</pre>		</pre>

			== Tips ==
			* By default logs are not persistent (/var/log points to /tmp). To have persistent logs with rotation every 1Mbytes, one can try to add this to his post_build.sh script:
			<code source="bash">
			# for persistent and rotating log messages
			rm -rf $1/var/log
			mkdir $1/var/log
			sed -i -e 's/SYSLOGD_ARGS=""/SYSLOGD_ARGS="-s 1024 -b 10"/' $1/etc/init.d/S01syslogd
			</code>

JulienB: /* Buildroot packages */

2025-10-07T12:48:33Z

Buildroot packages

← Older revision		Revision as of 14:48, 7 October 2025
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	</pre>		</pre>

	Then go to following menu :		Then go to following menu and choose your prefered syslog implementation ;-):
	<pre class="config">		<pre class="config">
	~~Package Selection for the target~~ --->		Target packages --->
	System tools --->		System tools --->
	...		...
	[ ] rsyslog		[ ] rsyslog
	[ ] ~~syslogd & klogd~~		...
			[ ] sysklogd
			...
			[ ] syslog-ng
	...		...
	</pre>		</pre>

FabienM: /* Basis */

2013-10-16T14:51:19Z

Basis

← Older revision		Revision as of 16:51, 16 October 2013
Line 1:		Line 1:
	= Basis =		= Basis =
			==Calling syslog method from shell==
			To do that, use '''logger''' command :
			<pre class="target">
			# logger -t "MYTAGNAME" "I like otters with cream"
			</pre>

			You can then see the message in /var/log/messages:
			<pre class="target">
			# tail /var/log/messages
			...
			Oct 16 16:50:13 armadeus user.notice MYTAGNAME: I like otters with cream
			</pre>

	==Calling syslog method from your C source code==		==Calling syslog method from your C source code==

FabienM: /* Buildroot packages */

2013-09-12T08:24:00Z

Buildroot packages

← Older revision		Revision as of 10:24, 12 September 2013
Line 77:		Line 77:
	</pre>		</pre>

	~~Then select~~ option :		Select option :
	<pre class="config">		<pre class="config">
			Package Selection for the target --->
			[*] Show packages that are also provided by busybox
			</pre>

			Then go to following menu :
			<pre class="config">
			Package Selection for the target --->
			System tools --->
			...
			[ ] rsyslog
			[ ] syslogd & klogd
			...
	</pre>		</pre>

FabienM at 08:20, 12 September 2013

2013-09-12T08:20:33Z

@@ Line 1: / Line 1: @@
 ==Calling syslog method from your C source code==
 This part is quite simple, but we need to correctly use each parameter.
@@ Line 50: / Line 52: @@
 </pre>
 We can notice, that the lines contain program_name[PID] pattern showing us the name we have specified in openlog and the pid of the process because we ask it with LOG_PID argument.

JulienB: /* Calling syslog method from your C source code */

2012-09-21T12:40:23Z

Calling syslog method from your C source code

← Older revision		Revision as of 14:40, 21 September 2012
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	==Calling syslog method from your C source code==		==Calling syslog method from your C source code==
	This part is ~~quiet~~ simple, but we need to correctly use each parameter.		This part is quite simple, but we need to correctly use each parameter.
	First step is to declare us as syslog client :		First step is to declare us as syslog client :
	<source lang="C">		<source lang="C">

SebastienR at 16:53, 19 September 2012

2012-09-19T16:53:04Z

← Older revision		Revision as of 18:53, 19 September 2012
Line 21:		Line 21:
	...		...
	</source>		</source>
	if you compile the source file:		If you compile the source file:
	<source lang="C">		<source lang="C">
	// log_syslog.c		// log_syslog.c
Line 28:		Line 28:
	int main(int argc, char *argv[])		int main(int argc, char *argv[])
	{		{
	openlog("program_name", LOG_PID, LOG_USER);		openlog("program_name", LOG_PID, LOG_USER);
	syslog(LOG_INFO, "%s called with %d arguments", argv[0], argc - 1);		syslog(LOG_INFO, "%s called with %d arguments", argv[0], argc - 1);
	closelog();		closelog();
			return 0;
	return 0;
	}		}
	</source>		</source>
Line 44:		Line 43:
	itsme@mycomputer:~/log_syslog$ ./log_syslog pim pam poum		itsme@mycomputer:~/log_syslog$ ./log_syslog pim pam poum
	</pre>		</pre>
	You will probably obtain no result in shell, but you can take a look in ~~you're~~ system log (/var/log/syslog or /var/log/messages)		You will probably obtain no result in shell, but you can take a look in your system log (/var/log/syslog or /var/log/messages)
	<pre class="apf">		<pre class="apf">
	itsme@mycomputer:~/log_syslog$ tail -n 2 /var/log/syslog		itsme@mycomputer:~/log_syslog$ tail -n 2 /var/log/syslog

SebastienR: New page: ==Calling syslog method from your C source code== This part is quiet simple, but we need to correctly use each parameter. First step is to declare us as syslog client : ....

2012-09-19T16:50:53Z

New page: ==Calling syslog method from your C source code== This part is quiet simple, but we need to correctly use each parameter. First step is to declare us as syslog client : <source lang="C"> ....

New page

==Calling syslog method from your C source code==
This part is quiet simple, but we need to correctly use each parameter.
First step is to declare us as syslog client :
<source lang="C">
...
#include <syslog.h>

int main(int argc, char *argv[])
{
...
openlog("program_name", LOG_PID, LOG_USER);
...
closelog();
...
}
</source>
Then, you can call syslog from your code using printf like format :
<source lang="C">
...
syslog(LOG_INFO, "%s called with %d arguments\n", argv[0], argc);
...
</source>
if you compile the source file:
<source lang="C">
// log_syslog.c
#include <syslog.h>

int main(int argc, char *argv[])
{
openlog("program_name", LOG_PID, LOG_USER);
syslog(LOG_INFO, "%s called with %d arguments", argv[0], argc - 1);
closelog();

return 0;
}
</source>
With the command :
<pre class="apf">
itsme@mycomputer:~/log_syslog$ gcc log_syslog.c -o log-syslog
</pre>
Then run it 2 times :
<pre class="apf">
itsme@mycomputer:~/log_syslog$ ./log_syslog
itsme@mycomputer:~/log_syslog$ ./log_syslog pim pam poum
</pre>
You will probably obtain no result in shell, but you can take a look in you're system log (/var/log/syslog or /var/log/messages)
<pre class="apf">
itsme@mycomputer:~/log_syslog$ tail -n 2 /var/log/syslog
Sep 19 18:46:49 mycomputer program_name[3022]: ./log_syslog called with 0 arguments
Sep 19 18:46:53 mycomputer program_name[3023]: ./log_syslog called with 3 arguments
</pre>
We can notice, that the lines contain program_name[PID] pattern showing us the name we have specified in openlog and the pid of the process because we ask it with LOG_PID argument.